Developing a capacitance readout circuitry for a directional MEMS sound sensor and sound source localization in a sensor network environment

Abstract

Locating sound sources has many industrial and military applications. One particular application that is of interest to the military is locating enemy shooters. Current systems that are used for this purpose are bulky, heavy and do not employ networking, which can improve the performance, reliability and accuracy. In this study we investigate the possibility of designing such a system that is small, distributed, cost effective and reliable. In the first part of this thesis, an electronics readout circuitry was designed for a directional Micro Electro-Mechanical (MEMS) sensor that is being developed in Naval Postgraduate School, Physics department. Readout circuit was optimized based on the sensor characteristics and optimal operation. The design of the sensors was also improved with the findings and submitted for fabrication. In the second part of the thesis, we looked at the possible applications using this sensor in a sensor network environment to effectively localize sound sources. Localization accuracy that can be achieved for a particular network size was investigated with simulation for different angular measurement uncertainties. Localization methods proposed in the literature were surveyed and compared. They were found not to be fully applicable to the problem at hand. Therefore a new method was proposed for localization in sensor networks with Angle of Arrival type of sensors.